Advertisements
Advertisements
प्रश्न
The plates of a parallel-plate capacitor are made of circular discs of radii 5⋅0 cm each. If the separation between the plates is 1⋅0 mm, what is the capacitance?
उत्तर
The capacitance of a parallel-plate capacitor is given by `C = (∈_0A)/d`
Here ,
A = Area of the plate
d = Distance between the parallel plates
Given :
`A = pir^2 = pi xx (5 xx 10^-2)^2`
`d = 1.0 xx 10^-3 "m"`
`∈_0 = 8.85 xx 10^-12 F/m`
`therefore C = (∈_0A)/d`
= `(8.85 xx 10^-12 xx 3.14 xx 25 xx 10^-4)/10^-3`
= `6.95 xx 10^-5 uF`
APPEARS IN
संबंधित प्रश्न
A bulb is connected in series with a variable capacitor and an AC source as shown. What happens to the brightness of the bulb when the key is plugged in and capacitance of the capacitor is gradually reduced?
(i) Find equivalent capacitance between A and B in the combination given below. Each capacitor is of 2 µF capacitance.
(ii) If a dc source of 7 V is connected across AB, how much charge is drawn from the source and what is the energy stored in the network?
As `C = (1/V) Q` , can you say that the capacitance C is proportional to the charge Q?
The equivalent capacitance of the combination shown in the figure is _________ .
Three capacitors of capacitances 6 µF each are available. The minimum and maximum capacitances, which may be obtained are
Take `C_1 = 4.0 "uF" and C_2 = 6.0 "uF"` in figure . Calculate the equivalent capacitance of the combination between the points indicated.
Find the equivalent capacitances of the combinations shown in figure between the indicated points.
Find the capacitance of the combination shown in figure between A and B.
Each of the plates shown in figure has surface area `(96/∈_0) xx 10^-12` Fm on one side and the separation between the consecutive plates is 4⋅0 mm. The emf of the battery connected is 10 volts. Find the magnitude of the charge supplied by the battery to each of the plates connected to it.
The separation between the plates of a parallel-plate capacitor is 0⋅500 cm and its plate area is 100 cm2. A 0⋅400 cm thick metal plate is inserted into the gap with its faces parallel to the plates. Show that the capacitance of the assembly is independent of the position of the metal plate within the gap and find its value.
Figure shows two parallel plate capacitors with fixed plates and connected to two batteries. The separation between the plates is the same for the two capacitors. The plates are rectangular in shape with width b and lengths l1 and l2. The left half of the dielectric slab has a dielectric constant K1 and the right half K2. Neglecting any friction, find the ration of the emf of the left battery to that of the right battery for which the dielectric slab may remain in equilibrium.
Obtain the expression for energy stored in the parallel plate capacitor.
Derive the expression for resultant capacitance, when the capacitor is connected in parallel.
A capacitor is charged by a battery. The battery is removed and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of resulting system ______.
The radius of a sphere of capacity 1 microfarad in the air is ______
A leaky parallel plate capacitor is filled completely with a material having dielectric constant K = 5 and electric conductivity σ = 7.4 × 10-12 Ω-1 m-1. If the charge on the plate at the instant t = 0 is q = 8.85 µC, then the leakage current at the instant t = 12 s is ______ × 10-1 µA.
A capacitor of capacity 2 µF is charged to a potential difference of 12 V. It is then connected across an inductor of inductance 0.6 mH. The current in the circuit at a time when the potential difference across the capacitor is 6.0 V is ______ × 10-1A.
Current versus time and voltage versus time graphs of a circuit element are shown in figure.
![]() |
![]() |
The type of the circuit element is ______.
A capacitor with capacitance 5µF is charged to 5 µC. If the plates are pulled apart to reduce the capacitance to 2 µF, how much work is done?